The present invention relates to a seal member which is preferable for use at a location through which a pass-through member is allowed to pass.
For example, a cooling structure is adopted for preventing the excessive heating of a high-voltage electrical equipment box which incorporates therein electrical equipment such as a battery and a control unit used on electric vehicles and hybrid vehicles which facilitate heat generation by allowing air to flow through the interior of the high-voltage electrical equipment box to carry away heat so generated to the outside of the box together with the air. As a cooling structure of this type, there exists, for example, a cooling structure in which an air inlet is provided on one side of a high-voltage electrical equipment box and an air outlet is provided on the other side of the same box, and a fan is mounted at the air outlet for forcibly discharging air from the high-voltage electrical equipment box, so that air is taken into the high-voltage electrical equipment box from the air inlet, then is passed through the interior of the high-voltage electrical equipment box and is finally discharged from the same box through the air outlet.
Incidentally, with the cooling structure described above, air needs to be prevented from being taken into the high-voltage electrical equipment box from other portions than the air inlet in order to cool the electrical equipment with good efficiency. Namely, in case air is taken into the high-voltage electrical equipment box from other portions than the air inlet, the flow rate of air in portions of the box which exist upstream of a portion or portions from which air is taken into the box is reduced, and therefore, the cooling efficiency of electrical equipment disposed upstream of the portion or portions where air is taken into the box is deteriorated. To cope with this problem, the sealing capability relative to a pass-through member such as a cable that is introduced into the high-voltage electrical equipment box from the outside to be connected to the electrical equipment in the box needs to be secured at a pass-through portion in a wall portion of the high-voltage electrical equipment box, and this results in use of, for example, a rubber seal member having formed thereon a flat and annular sealing portion having inside an opening through which a pass-through member is allowed to pass.
However, with the seal member which has the flat and annular sealing portion being used, in the event that a gap between the seal member and the cable is set to be closed, there was a case where the assembling property of the seal member was deteriorated as the fastening force increased.
In addition, a cable having a consistent diameter is not always used but a cable is sometimes used which has a large diameter portion provided at a position along a small diameter portion. In a case where sealing is implemented at the small diameter portion after the large diameter portion has been passed through the seal member, the use of a seal member is required which is formed into a shape having a slit formed in a sealing portion for allowing the large diameter portion to pass through the seal member. However, in case a slit like this is formed in the sealing portion, a certain amount of air is caused to flow through the slit, causing a problem that a sufficient level of sealing capability cannot be secured.
Note that a problem like the one described above happens at various types of sealing portions for preventing the flow of not only air but also various types of fluids or dust. In addition, a problem like the aforesaid problem also happens in a case where not only cables but also various types of pass-through members are allowed to pass through the sealing portions.